Diamond holder or dop for holding diamonds



March 1946.

' R SKY' DIAMOND HOLDER R D oP FOR HOLDING DIAMONDS Filed Mann 5, 1945 1w Wm Patented Mar. 5, 1946 1 r f DIAMOND HGLBER von DQP IioR HOLDING Y "DIAMONDS 1 t Leopold :Bartnovsky, New erk fl y,

Application March 3, 1945', Serial No. 580 743 oolaims. (ct-5.15229) This invention relates to diamond holders or so -called dops for "holding diamonds while t e same are being ground or polished, andt'the primary object of the invention is to provide a de ofthis' character by means of which speed and accuracy in'polishing-di'amonds may be attained.

'As'is well'understood'in this. 'art, the grindin and polishing of the various facets'on a diamond touniformly correct. angle and shape is of paramount: importance and'. thisrequires:v extremfc 'watchfulness on the part of theworkm'an, who

is constantly required torepe'ate'dly elevate the workfrom the polishing wheel to note progress off'the grinding andpolishing operation." The "present invention contemplatesthe provision of means by which uniformity ofoperation'for'each of -the-facets is assured since ajsignal meansis "provided by which the completion of the grinding and p'olishing'operation' on afacet is at onceindicated to the operatorwho can then adjustth'e diamondto position for-grinding and'polishi-ng of the next'facet.

More particularly, the invention contemplates the provision of a holder-having an adjustable contact finger adapted 'tO -be sopositioned that-its extremity-will be'located at a predetermined point one diamond held by the holder; such as at-the girdle of" the stone, whereby the extremity of the fingerwill be brought into contact with the sur- "f-aceor-the polishing wheel when the facet being rormed will be ground -to therequiredangle: The invention includes the provision of 1a suitablesignai device, such as a small'electric'ligh't; andan electric circuit therefonwhich will be closed to ignite thelight- *when'thecontact' finger is brought into contact with the-surface of the polishing wheel, thus indicating thatthegrinding or polishmeor a facet-on thestohe has been completed.

An object of, the invention is to provide in a deviee of this character means-by whichthe contact finger-=orfeeler may be easily and-swiftly adjusted to the correct point and by whichthe finger may begretracted to permit releaseor resetting of the diamond on: its; seat," yet may be" at once replaced -in its formersetting without adjustment.

These and other obfie'cts are accomplished" by the invention, a more particular description of which will behereinaiter set forth and pointed out in the'claims"appendedhereto.

Reference is to be had to the accompanying drawing, forming a part hereof, in which Fig. 1 is a side elevation of the holder, constructed in accordance with the invention; Fig. 2 is a front view of the same; Fig. 3 is a view of the contact finger mechanism; with a portion of the guide being shown in section, and-Fig. 4' is a side view of the finger removed from'its'guide means.

In the drawing. the body or headbfthe holder or don-is. indicatedat I, the same being provided w thiia pr iectine cml' by m ans of w ic t hol'derflis supported at the. proper angle at: the

tendofthe supporti arm T mo d ib roundt'and o ed'is h n he sam eing held a ainst a m n ast m which isadjustableiin the body of the holder in suita l ma n r o? th by pr er locate the seat to hold; 'azdiiamondofany' given size in pos t o t 'be g und nd ed "by a polis ing' wheelfagportion ofwhich is diagrammatically indicated at 30in Fig. '11 Thediamond 6 is held against the seat" 5"by means of a pair o t-curved 'fi'ngers "I; at least-one of which is adiidstable by means of the screw 24. These fingers 7;, in cooperation with the flange 2'3 onthe-seat, hold the diamond in position against the sea-t.

The body I of the holder is provided with a fiat face 3|, and secured thereto bymea-ns of the 'screwsffi' is a uide member 8. Extendin through the' guide member 7 8' is a passage 1 0 through which a threaded rod H is axially slidable. Said rod H- has a fixed head H at one endandisspl-it a-tits' opposite end to accommodate-a spring finger 19a; the finger being se- -,cured-'*in the split portion of the'rod by means of the rivets-20;- whereby it projects beyond the end ofth e --rod-1-in the mannerclearlyseen in Fig. 4:

j -Threadably= re'ceived'in one end of-the passage I0 is a bushing IE through which the-rod H is slida-ble, and; confined between the inner 'end'bfjthe bushing 15 and" a sleeve H secured "onthe rod 5H, is a coil' spring 16 which tendst'o urge the-rod out ofthe opposite end of the pasbushing H tothe rod; Said pirr is provided'with -a'-"pro iectingpart l9 extending laterally from the sleeve -or bushing l1 and movabl'e-in a slot 2| formedin' the wall cf'the guide member 8 and seen in Fig. 2.

Located in the slot 2| is a catch or detent 22 adapted to engage around the projecting part tracted against the pressure of the spring [6, as will be explained.

From the foregoing, the operation of the device will be readily understood. A diamond 6 is placed upon the seat and held thereon as previously described. By rotation of the adjusting nut [3, while the lock nut is in a retracted position, the rod H may be advanced or retracted through the passage to thereby position the tip or extremity of the spring contact finger I9a right at the girdle of the diamond, or at such point desired to limit the grinding or polishing operation. When this adjustment has been secured; the lock nut I4 is turned to bring it againstthe' nut l3 and thereby hold the position of the lat ter nut. The device is then ready for operation and the arm 3 is lowered to bring the diamond 6 against the rotating polishing wheel 30. The

polishing operation continues until the tip or the tremity, which may be of knife-edge form, of the finger l9a comes into contact with the surface of the polishing wheel, this serving to actuate .current. The other side of the battery connects to a suitable portion of the frame of the polishing. machine so that the wheel is thereby included in the circuit. The holder l, or the arm 3 to which the holder is attached, is connected to the lamp 25 so that it will be apparent that when the finger 19a contacts the wheel 30, circuit will be closed between 28 and 29 to illumihate the lamp and indicate to the operator that the grinding of a. facet to the proper angle has been completed.

When it is desired to shift the diamond to present another portion of it to the wheel 30, the spring finger l9a is moved out of the way or retracted. This is done, and without losing the adjustment of the finger, by grasping the head 12 and drawing the rod H out until the pin l9 is engaged by the detent 19. This engagement of the pin by the detent will cause the rod to be held in a retracted position against the pressure of the spring l6, until the diamond has been placed in position for the grinding of the next iii facet, whereupon a slight push on the head 12 I will cause the pin l9 to be moved past the detent 22 and allow the finger to be thrust forward under the pressure of the spring "5 to the extent determined by the previously adjusted stop rod and projecting from the guide and adapted to have its end located in a predetermined position relative to a diamond held against the seat,

spring means surrounding the rod and acting to urge the finger toward the diamond, and at least one adjusting nut on the rod to determine the extent to which the finger is urged by the spring means toward the diamond to indicate a. point to which the diamond shall be ground.

2. In a diamond holder or dop, a head having a seat against which a diamond is held, means for holding the diamond against the seat, a guide secured on the head, a rod slidable through the guide, a-spring finger onsaid-rod and projecting out of the guide to enable its end to be positioned as a predetermined point on the diamond held against the seat," a threaded portion on the rod, 'nuts adjustable on the rod to serve as stops thereonto limit the axial sliding movement of the rod through the guide in a direction toward the diamond, a spring for urging the rod toward the diamond to an extent permitted by the stops, and

catch means for holdingthe rod in a retracted position against the pressure of the spring.

7 3. In a, diamond holder ordop, a seat for holding a diamond, a guide located adjacent to the seat, a rod axially movable through the guide, a spring finger on the rod constituting an electrical contact member and adapted to have its end positioned at a predetermined point on the diamond by projection of the rod out of the guide for a selected. distance, rotative adjustment means on the rod for axially adjusting the rod through the guide, spring means for urging the rod toward the diamond to an extent permitted by the adjustment means, means for permitting manual retraction of the rod through the guide and a detent for holding the rod in a retracted position.

- 4. In a diamond holder or dop as called for in claim 3, including signal. means, an electrical circuit for actuating said signal means, the diamond holder being so connected into said circuit together with the polishing wheel against which it holds a diamond, that contact of the spring finger with said wheel will close the circuit to actuate'the signal means.

5. In a diamond holder or dop, a'seat against which a, diamond is he1d, a guide on the holder, a threaded rod slidable through the guide, a spring contained within the guide, a shoulder on the rod against which the spring is operative'to vurge the rod in a direction toward the diamond held against theseat, an adjustable stopon the threaded portion of the rod, a projection extending laterally from the rod, the guide having a slot in which said projection is movable, a detent located in the slot for engagement with the projection when-the rod is moved to a retracted position against the pressure of'the spring, and a contact finger carried at one end of the rod and adapted to be, positioned at a predetermined position relative to the diamond 'held against the seat, by axial adjustment of the rod through'the guide. a

6. A diamond holder or ,dop ascalled for in claim 5 andincluding an electrically actuated signal, andanelectric circuit-connected thereto and which circuit is closed to actuate the signal when the contact finger is brought against the surface of a polishing wheel against which the diamond is held by the holder or dopx J LEOPOLD BARTNOVSKY. 

